The feedback code is the last parameter of all Language Environment callable
services, and the second to last parameter of all Language Environment math
services. COBOL/370 programs
must provide the feedback code parameter in each call to a Language Environment callable
service; C, C++, Enterprise COBOL for z/OS, COBOL for OS/390 & VM, COBOL for MVS & VM, and PL/I routines
do not have to do so. (See z/OS Language Environment Programming Reference for
information about how to provide the feedback code parameter in each
HLL.) When the fc parameter is provided
and a condition is raised, the following sequence of events occurs:
- The callable service in which the condition occurred builds a
condition token for the condition. The condition token is a 12-byte
representation of a Language Environment condition.
Each condition is associated with a single Language Environment runtime
message.
- The callable service places information into the ISI, which might
contain the following:
- A timestamp
- Information that is inserted into a message associated with the
condition
For example, you can use the CEEBLDTX utility (see Creating messages) or the CEECMI callable service
(see z/OS Language Environment Programming Reference)
to generate message inserts. Routines signaling a new condition with
a call to CEESGL should first call CEECMI to copy any insert information
into the ISI associated with the condition.
- If the severity of the detected condition is critical (severity
= 4), it is raised directly to the condition manager. Language Environment then
processes the condition, as described in Condition step.
- If the condition severity is not critical (severity less than
4), the condition token is returned to the routine that called the
service.
- When the condition token is returned to your application, you
can use the condition token in the following ways:
- Ignore it and continue processing.
- Signal it to Language Environment using
the CEESGL callable service.
- Get, format, and dispatch the message for display using the CEEMSG
callable service.
- Store the message in a storage area using the CEEMGET callable
service.
- Use the CEEMOUT callable service to dispatch a user-defined message
string to a destination that you specify.
- Compare the condition token to one that is known to you so that
you can react appropriately. You can test the condition token for
success, equivalence or equality.
See z/OS Language Environment Programming Reference for
more information about Language Environment callable
services.